depends what trans you have. they all do basically the same thing, but if you have an electronic trans it's not just something you can eliminate. the governor is what regulates upshifts. on a chevy 700r4 and similar older transmissions it is a mechanical device that spins in relation to road speed. the faster you go the faster it spins. it is connected to a spool valve that directs fluid to different shift valves depending on position. the throttle valve on the other hand is connected to the throttle and fights the governor to prevent upshifts depending on throttle position.
"I don't have pet peeves, i have major psychotic fucking hatreds" -George Carlin